Abstract:
Colorectal cancer (CRC) is one of the most common malignant tumors in the world. The 2022 China Cancer Statistics Report shows that the incidence and mortality of colorectal cancer in my country ranks second and fouth among all malignant tumors, respectively. Among them, about 15% to 25% of CRC patients have had local and distant metastases at the time of diagnosis, and about 50% of patients with early CRC will have metastases during treatment, and about 80% to 90% of them have lost the opportunity for surgery. The survival rate is less than 10%; the current BRCA gene research is mostly focused on breast, ovarian, and pancreatic cancer, and is relatively rare in colon cancer and other tumors. This article reports a case of advanced colon cancer diagnosed and treated in our department with BRCA gene mutation Cases, hoping to provide clinical reference for BRCA genes in other tumors.
The male patient, 32 years old, was admitted to a local hospital in October 2016 for intestinal perforation. Emergency laparotomy revealed multiple liver surface nodules, and biopsy confirmed invasive metastatic moderately differentiated adenocarcinoma. He was transferred to our hospital's general surgery department, where colonoscopy identified advanced-stage hepatoperitoneal cancer. Upper abdominal MRI showed abnormal signals in the hepatic region of the colon. Considering his medical history, we diagnosed colorectal cancer with multiple hepatic lesions and enlarged lymph nodes near the abdominal aorta. He received five cycles of CapeOX chemotherapy regimen.The treatment achieved PR response. In March 2017, acute intestinal obstruction occurred. Palliative surgery was performed (radical right hemicolectomy with partial hepatic resection, radiofrequency ablation of metastatic liver lesions, and extensive adhesiolysis). Postoperative pathology confirmed right hemicolectomy with mucinous cell carcinoma. AJCC staging: pT3N2bM1a. Immunohistochemistry showed CK (+), CEA (+), CK8/18 (+), MLH1 (+), PMS2 (+), MSH2 (-), and MSH6 (-) ?Postoperative chemotherapy continued with the CapeOx regimen for three cycles. Due to elevated CEA levels and MRI findings showing increased liver tumors , the treatment was switched to the FOLFOXIRI regimen. After two cycles, disease progression (PD) was observed. In July 2017, MRI revealed increased multiple metastatic lesions in the liver . The treatment was adjusted to targeted therapy combined with chemotherapy: Bevacizumab 300mg IV daily, Istitutimab 200mg IV daily, and Capecitabine 1.5g orally daily for six cycles, achieving progression-free response (PR). Following significant CEA elevation in December 2017, immunotherapy was initiated after consultation with family members: PD-1 monoclonal antibody (Pembrolizumab) 100mg IV 30-minute daily for 12 cycles, maintaining PR. In June 2019, MRI showed markedly enlarged lymph nodes in the hepatic hilum, mesenteric root, and retroperitoneal region . The treatment was then changed to Bevacizumab plus m-F0LF0X6 chemotherapy for three cycles. Subsequently, due to oxaliplatin allergy, the regimen was modified to Bevacizumab plus simplified bimonthly 5-FU infusion/LV regimen, achieving PR.Following persistent enlargement of cervical lymph nodes, the patient underwent MTD (Multimodal Diagnostic) evaluation. Cervical lymph node biopsy confirmed mucinous cell carcinoma. Immunohistochemical analysis showed: CK7 focal positivity, CK20 positivity, CK8/18 positivity, CDX2 positivity, Villin positivity, TTF negativity, CK5/6 negativity, P63 negativity, focal P53 positivity, S100 negativity, and CD117 negativity, with a Ki-67 index of approximately 80%. Genetic testing was performed. Following guideline recommendations and genetic test results, we initiated Xindiximab 200mg + Regorafenib combined with Oxaliplatin in February 2020. During oxaliplatin infusion, systemic rash developed, leading to discontinuation of the infusion. The treatment regimen was adjusted to Xindiximab + Regorafenib combined with cisplatin for 3 cycles. MRI follow-up demonstrated significant reduction in the hepatic apex lesion , with an efficacy evaluation of SD. Current status: stable, with regular hospital visits for immunotherapy and targeted therapy.
